The lifecycle of a mobile app does not end after the initial submit to the mobile stores. You have to fix bugs, change existing features and add new features. With a native application you only have the option to re-submit every new app version to the stores and wait for their approval.

With Cordova / PhoneGap (and React Native) apps you have an additional option. These frameworks wrap JavaScript applications inside a native wrapper and are able to update, with the help of a plugin, the containing resources on the fly. This way you can update, remove and add JavaScript, HTML, CSS files and assets like pictures, music without re-submitting the whole application to the stores. You can only update the resources that are embedded in the native wrappers. There is no way to update the wrapper itself. If you add a new Cordova plugin to an app, you always have to re-submit the app.

One question that always comes up if you talk about these kinds of update is if Apple allows that. According to the iOS Developer Program these on the fly updates are allowed as long as you don't change the main purpose of the application. Don't transform your calculator app into a game.

3.3.2 Except as set forth in the next paragraph, an Application may not download or install executable code. Interpreted code may only be used in an Application if all scripts, code and interpreters are packaged in the Application and not downloaded. The only exceptions to the foregoing are scripts and code downloaded and run by Apple's built-in WebKit framework or JavascriptCore, provided that such scripts and code do not change the primary purpose of the Application by providing features or functionality that are inconsistent with the intended and advertised purpose of the Application as submitted to the App Store.

In this article we have a look at how you can hot update an Ionic / Cordova app with Ionic Appflow Live Deploy. The service is part of Appflow. Ionic offers a free tier which includes deployments to 100 devices per month.

After you created the app in the Appflow dashboard, Appflow assigns a unique number to your project. In this example it's the id 512fe61e.

If you already have an Ionic app you can link it to Appflow with the following command.

ionic link --pro-id 512fe61e

But for this tutorial I start from scratch. The following command creates a new project with the name myapp, based on the blank starter template and linked to the Appflow project. Replace <pro-id> with the id of your project.

ionic start myapp blank --type=angular --pro-id <pro-id>
cd myapp

The start command asks which Git hoster it should use. You have the choice between Ionic Appflow and GitHub. For this example I host the project on Ionic Appflow.

Now open the file src/app/home/home.page.html and insert the following code. This allows us to verify if the update process works or not.

Next we set up Cordova. Live Deploy also works with apps installed on iOS but for this tutorial I only have access to an Android device.

ionic cordova prepare android

Then we need to install the Cordova Ionic plugin. Login to the Appflow Dashboard, open the Deploy and Channels menu and click on Set up Deploy.

You can choose between the following update methods.

With the methods auto and background, the plugin automatically manages the update. But you can control everything manually by selecting the third option none. The Ionic plugin provides an API that can manage the whole update lifecycle via TypeScript code. See the documentation page for more information.

For this example I select the auto method. The plugin will, in this mode, download the updates during app start and install them immediately.

To create an update we change the version in the src/app/home/home.page.html file.

<ion-card-content>
0.0.2
</ion-card-content>

And then commit the change and push it to Ionic Appflow

git commit -am "v0.0.2"
git push ionic master

Open the Appflow Dashboard. Select the menu Deploy / Builds. Click on New web build. The dashboard displays a list of commits. Click on the latest commit, select the channel Master and click on Create build.

Appflow now builds the app and publishes it to the Master channel. Wait until the build is finished. Open the Deploy / Builds menu and verify that the build is assigned to the Master channel. If not click on the arrow up icon and deploy the build to the channel.

To test the update process. Close the app on the device and re-open it. After a few seconds, you should see the updated version of your app.